Reference : Evidence of magnetic field decay in massive main-sequence stars
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/205395
Evidence of magnetic field decay in massive main-sequence stars
English
Fossati, L. [Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042, Graz, Austria ; Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany]
Schneider, F. R. N. [Department of Physics, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK; Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany]
Castro, N. [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany]
Langer, N. [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany]
Simón-Díaz, S. [Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain]
Muller, Aline [> > > >]
de Koter, A. [Astronomical Institute Anton Pannekoek, Amsterdam University, Science Park 904, 1098 XH, Amsterdam, The Netherlands; Instituut voor Sterrenkunde, Universiteit Leuven, Celestijnenlaan 200 D, 3001, Leuven, Belgium]
Morel, Thierry mailto [Université de Liège > > Groupe d'astrophysique des hautes énergies (GAPHE) >]
Petit, V. [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL, 32904, USA]
Sana, H. [Instituut voor Sterrenkunde, Universiteit Leuven, Celestijnenlaan 200 D, 3001, Leuven, Belgium]
Wade, G. A. [Department of Physics, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4, Canada)]
1-Aug-2016
Astronomy and Astrophysics
EDP Sciences
592
Yes (verified by ORBi)
International
0004-6361
1432-0746
Les Ulis
France
[en] stars: atmospheres ; stars: massive ; stars: evolution ; stars: magnetic field
[en] A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of massive stars are currently not well understood. We compile a catalogue of 389 massive main-sequence stars, 61 of which are magnetic, and derive their fundamental parameters and ages. The two samples contain stars brighter than magnitude 9 in the V-band and range in mass between 5 and 100 M[SUB]⊙[/SUB]. We find that the fractional main-sequence age distribution of all considered stars follows what is expected for a magnitude limited sample, while that of magnetic stars shows a clear decrease towards the end of the main sequence. This dearth of old magnetic stars is independent of the choice of adopted stellar evolution tracks, and appears to become more prominent when considering only the most massive stars. We show that the decreasing trend in the distribution is significantly stronger than expected from magnetic flux conservation. We also find that binary rejuvenation and magnetic suppression of core convection are unlikely to be responsible for the observed lack of older magnetic massive stars, and conclude that its most probable cause is the decay of the magnetic field, over a time span longer than the stellar lifetime for the lowest considered masses, and shorter for the highest masses. We then investigate the spin-down ages of the slowly rotating magnetic massive stars and find them to exceed the stellar ages by far in many cases. The high fraction of very slowly rotating magnetic stars thus provides an independent argument for a decay of the magnetic fields.
http://hdl.handle.net/2268/205395
10.1051/0004-6361/201628259
http://adsabs.harvard.edu/abs/2016A%26A...592A..84F

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